As is known in the art, many systems include multiple processors that need to communicate efficiently. Packet-processing devices, for example, can include network processors and other processor types. Network processors can be used to pass data traffic to various networks over different network interfaces. In general, network processors are optimized to process packets at high speeds. Network processors typically include multiple programmable packet-processing engines or elements running in parallel with mechanisms for the processing engines to communicate with each other. Network processors can include a general purpose microprocessor to handle control tasks and memory controllers to facilitate movement of packets in and out of external memory. Network processors can further include interface modules for one or more standardized interfaces. Additional network processor modules can include coprocessors for accelerating various functions, such as encryption and decryption. Some network processors, such as the IXP family of network processors by Intel Corporation, have multiple cores on a single die. Communication between the cores is accomplished through hardware-supported queuing mechanisms implemented in the memory controller(s).
In certain applications, it is desirable for a network processor, for example, to have high-speed communication with a processor having an architecture different from the network processor. Existing inter-processor connections schemes have limited bandwidth. For example, PCI (Peripheral Component Interconnect) can be used to enable communication between processing elements in a network processor, such as an Intel IXP 2800 network processor, and another processor type, such as an Intel Pentium™ processor. However, this arrangement provides limited bandwidth, such as less than 1Gbps (bit per second) for 128 byte transfers.